To paraphrase Dr. Demento, dead 6-year-olds aren't much fun. In "Capture Now," writer-performer Josh Jonas tells us right off the bat that the kid we're hearing about is going to die.

To paraphrase Dr. Demento, dead 6-year-olds aren’t much fun. In “Capture Now,” writer-performer Josh Jonas tells us right off the bat that the kid we’re hearing about is going to die. But he assures us that, “just like Romeo and Juliet,” his main character Elijah and his doomed little brother Ace “are gonna go nuts for each other.” If only the audience could muster the same affection for Jonas, who performs his own sporadically funny script with some polish — helmer Larry Moss is a well-known acting teacher — but no real insight.

“Capture Now” is a little like a dramatization of the poems of Mattie Stepanek without the personal understanding of cancer — Elijah’s troubles at school and with his parents ring far truer than his completely frictionless relationship with Ace. No teenager was ever this nice to his toddler brother.

It would be easier to summon sympathy for Jonas himself if he were telling his own story. Reportedly, though, “Capture Now” was inspired by a friend’s loss of a child, and so Jonas has about the same level of understanding that a well-meaning comforter might bring to a friend at a funeral.

Moss has made a habit of adopting interesting one-man shows — last season’s “Runt of the Litter,” a much better play about feuding brothers on opposing football teams, had the same kind of carefully crafted performance.

“Capture Now,” however, doesn’t benefit from Moss’ coaching in the same way. Jonas’ every move is confident and determined — at times, you can see the mime exercises giving his performance that little extra boost. Even during the embarrassing “tough guy” sequence, in which Elijah orders food at a diner while talking like a goodfella for Ace’s benefit, Jonas has complete control. The problem, in the performance and in the script, is dishonesty.

“This doesn’t mean we’re all helpless, ya know?” says the boys’ father in response to the news that his son is probably going to die. In fact, that is what it means, and “Capture Now” would have been much more truthful had it examined that reality more closely instead of shying away from it. There’s no law saying a writer has to have experienced deep personal loss in order to write about it. But when a play about a dying child finally dispenses with all the cutesy crap and has to stare death right in the face, it had better not blink.

Jonas chickens out. Instead of dealing with death, he seems most interested in making his audience cry, at which he has some success. But it’s hard to imagine anyone will thank him for this.

Structurally, “Capture Now” has some real advantages. The dramaturgy is tight, and every single character Jonas introduces comes back into the plot in an interesting way. Strangely, the piece is both too ambitious and not ambitious enough — Jonas wants an emotional connection to his audience, but he’d rather not challenge them to get it.

Capture Now

Theaters at 45 Bleecker; 99 seats; $56.50 top

Production

A Kurt Petersen and Jane Bergere presentation of a solo show in one act, written and performed by Josh Jonas. Directed by Larry Moss.